Three Lights

Introduction

Many people who are new to the 3D graphics hobby begin by using the built-in features of tools like Poser and DAZ Studio which stop new artists from shooting themselves in the foot when it comes to lighting their scenes. Namely, the tools add one (or more) default lights to a scene so that your image doesn’t turn out a big black nothing. From there they may go on to using pre-built light sets that they get for free or that are included in some sets they buy.

But often I see artists who stop there or who express a bit of trepidation at the idea of adding their own lights to a scene. In this tutorial, I’m going to talk about how to setup a very common lighting rig that photographers use for portrait style photographs. As you might imagine, it also works well for portrait style 3D renders.

The Setup

For the scene, I decided to use Victoria 4.2 from DAZ 3D as my main character. The skin, clothing, and hair all come from Alfaseed and are available at the Runtime DNA online store. Finally the scenery is from a set called Japanese Flair. To be honest, I’m not entirely sure where I got that. I’m using DAZ Studio 4.6 for my rendering tool.

The lights I’m going to be adding are all stock spotlights. I have other lights in my content library that give me more control, but I wanted to show what you can accomplish using the built in lights first. For shadows I used raytraced shadows on all of the spotlights. I don’t care for how DAZ Studio handles deep shadow maps especially when it somes to hair; so I rarely (if ever) use them.

After I got Vicky dressed, I put her on the table in the pose I was looking for, arranged the screen in the background, and framed the shot in the camera. I didn’t want an extreme closeup of her face as I wanted to get some of the details of the Amp’d Lemonade outfit and the IIve skin as well. Then, just to see how things looked, I went ahead and hit the render button.

As I mentioned earlier, DAZ Studio helps out the new artist by adding a light at render time if you haven’t explicitly added any so there is some to see. But the light is just a simple light as if it were mounted on top of the camera, not very interesting. Still, this is a good way to render a scene when you’re still working on posing and such since it renders fast as the default light doesn’t have ray tracing or shadows or anything to worry about.

Main Light

The first light I add to the scene is my main light. In this case, I want my main light to light Vicky’s face but also leave some shadows with her hair; so I’m going to put it slightly above and to the left of the camera position. When I’m placing lights, in DAZ Studio, I typically switch my view to the Perspective View, move around until I’m where I want the light to be, then insert the light, telling DS to copy my current position and orientation. The light ends up being located like this…

The next thing I do is to make sure the light is pointed where I need it to. Now in a normal scene where my lights are simulating light generated by objects in the scene, I don’t always care where they are pointed. But in this case this rig is being setup to light my portrait subject; so for each light I’m going to target the portion of the subject that the light should be centered on. In the case of the Main light, I point it at Vicky’s head. The screen snips below show how I got there…

For now, I’ll leave the color set to white (255,255,255) and intensity set to full (100%) and render to see the results of adding the main light.

I think you can quickly see that this is more dramatic than the default “camera light” shown above. However there are clearly some issues. Like the very dark deep shadow behind her back. To alleviate that, we need to add a fill light.

Fill Light

The purpose of the fill light is to provide some light to soften the shadows opposite the main light, but still allow for there to be a contrast between the two sides of the subject. If we were to light them both evenly, the result would look flat an uninteresting. A fill light is typically at a lower angle as well since you want it to fill in some light in the shadows that your higher main light is creating. I’ll drop my fill light below and to the right of my camera like this:

For now, I leave this light as white at 100% intensity as well. In the case of the fill light, I don’t want it to point up at Vicky’s head, I want the fill light centered lower on that black shadow behind her back; so I’ll have this light point at her hip.

To see the effect of just the fill light, I first turn off the main light and render the fill light itself.

Then I turn on the main light to see what they look like together.

Looks over exposed, doesn’t it? It is. The fill light should only be about 20-30% of the strength of the main light, but we’ll address that later. For now, on to the third light in the setup.

Rim Light

The third light is called the rim or key light. This light is placed behind and often above the subject. The purpose of the rim light is to add some highlights that help outline the subject and seperate him/her from the background.

Note: In photography some interesting effects are often done by putting the rim light behind or below the subject. The problem in 3D graphics is that usually 3D hair doesn’t react with the proper translucency to achieve the glowing effect that photographers can get with their cameras.

I’ll place my rim light very high and just slightly behind Vicky like this:

Again I leave the color and intensity with the defaults. Then I set the point at target. I could use Vicky’s head again. But techincally what I really want to highlight with this light is her hair; so I target the fantasy drops hair instead.

I turn off the main and fill lights to check how the rim light is looking…

Just shows the highlights (as we’d expect). So I turn on the other 3 lights and render to see them all…

Well that’s … different … but way too bright time for some tweaking.

Tweaking the Lighting

First thing I need to do is adjust the intensity settings. I typically use 30% for the fill light and 90% for the rim. I could keep the rim at 100% (it isn’t adding THAT much light after all) but I don’t need that much more main lighting than what my Main was already adding. Here’s the effect of just adjusting the intensity levels.

Much better! But when I’m lighting a portrait, I typically don’t like the cold harsh white lighting that comes from the default. I prefer to warm up the main light and cool off the fill and rim lights some. I played around with colors a little. Since the hair and skin have some blue and green tones I went a bit cooler on the fill and rim lights than I might normally, but the new settings worked out. I went with the following R,G,B values:

Main : 255, 250, 242

Fill: 240, 245, 255

Rim: 245, 250, 255

The result was this image which I decided to call “good enough” (for me that means “final”):

Modifications

I’ve had some people ask me before if 3 lights wasn’t too limiting. To which I say not at all! Here are a couple of examples of quick tweaks I did which change the image significantly.

Cool Blue

First by cooling off all of the lights even more, I can take a normal portait style image and make it look noctournal and/or otherwordly.

Devil in Disguise

Next I dropped the main light below Vicky. This meant I had to move my fill light closer to the camera. Doing that, I lost some details on the shoulders and hair; so I slid the rim light around so it was behind her head between her shoulders just off the end of the table. This is where those “point at” settings really paid off as I only had to move the lights without having to re-focus them on my subject!

Lighting a subject from below gives them a more sinister look. If you watch old movies, you’ll see that effect used a lot on the villians. I changed nothing at all about Vicky. And yet her smile looks much more mischievious in this image. Also I really like how the fill light casts the shadow on the screen.

Conclusion

I hope that this gives you some understanding of how you can use a fairly simple lighting setup to create portrait style rendered images. Once you get your hands on placing and working with lights yourself I think you’ll find they aren’t nearly as daunting as you may think they are!